Day 3 of the U.S. Open saw more extreme heat and humidity with some outside courts reaching 110 degrees or more. While some players like new darkhorse favorite Ana Ivanovic, who cruised into the third round with an easy win over Jie Zheng, said later it didn’t bother her, others like veteran Ivan Ljubicic who lost to American teenager Ryan Harrison, cited the steamy conditions as a factor for their early exit from New York. Throw in gusty winds from approaching Hurricane Earl and it made for a wild weather day. But the biggest story wasn’t the weather at all, but a shocking exit by pre-tourney favorite Victoria Azarenka, who was literally knocked out of the U.S. Open.

Azarenka, who collapsed on court during the first set of her second round match against Gisela Dulko, was escorted out in a wheelchair and then taken to a local hospital. At first, many thought she suffered from heat exhaustion but later Azarenka issued a statement saying, “I was warming up in the gym prior to my match against Gisela Dulko. I fell while running a sprint. I fell forward and hit my arm and head. I was checked by the medical team before I went on court and they were courtside for monitoring. I felt worse as the match went on, having a headache and feeling dizzy. I also started having trouble seeing and felt weak before I fell. I was taken to the hospital for some medical tests and have been diagnosed with a mild concussion.”

Meanwhile a shifting of sorts in terms of young American talent to watch took place as qualifier Ryan Harrison took out No. 15 seed Ivan Ljubicic in four sets. Harrison, who had been given wildcards in the last two U.S. Opens, later said he thought having to go through qualifying helped his chances today. “Playing on these courts week before, winning matches, I mean, winning builds and confidence builds winning. It goes back and forth. But winning those three matches and, you know, getting used to the courts and used to playing a certain style of play has helped me an extreme amount going into today.” That wasn’t the case for another American hopeful wildcard Donald Young who was quickly dispatched in three sets by Gilles Simon of France in under 80 minutes. Many felt Young didn’t deserve the wildcard due to his low ranking and poor results this year and it may be that Young will now have to rely on himself to make it into the main draw next year.

Other American winners included Venus Williams, Sam Querrey and John Isner who many thought would not play due to his ankle injury suffered in Cincinnati. Isner delivered a three set win over Frederico Gill to the delight of the American crowd but it’s still questionable how Isner will fare in later rounds against tougher opponents. Finally, “Oudin Mania” as the U.S. Open website described it finally came to an end after a year long media whirlwind over 18-year-old Melanie Oudin whose quarterfinal run last year in New York made her household name. However, Oudin’s shaky form in 2010 caught up with her today as she couldn’t fight off No. 29 seed Alona Bondarenko who won 6-2, 7-5.

Oudin’s loss will drop her ranking down to the low 70’s and also make her, for the moment, the fourth best U.S. woman behind Bethanie Mattek-Sands and the Williams Sisters. If Oudin’s game can improve and rise to the top of the WTA tour is still up to her, but perhaps now the media will give her a little more room to focus on her game. But that doesn’t mean that they won’t be on the hunt for the next “the One” who could be America’s newest tennis star. Young and Oudin certainly know the pressure of living up to that title. We’ll see how well Harrison handles it himself especially if wins his second round match against Sergiy Stakhovsky later this week.